The paper buried at the bottom of the article is recommended over the superficial article. https://iopscience.iop.org/article/10.3847/1538-4357/ac3df9 https://

The paper buried at the bottom of the article is recommended over the superficial article. https://iopscience.iop.org/article/10.3847/1538-4357/ac3df9 https://iopscience.iop.org/article/10.3847/1538-4357/ac3df9 https://iopscience.iop.org/article/10.3847/1538-4357/ac3df9/pdf https://iopscience.iop.org/article/10.3847/1538-4357/ac3df9/... I was balking at the term "optical illusion", and it turns out that the word "illusion" never even appears in the paper. The paper has a lot of excellent illustrations and simulation photos.